I agree with what you are saying there but i think you missed my point.

Lets say we have 2 RS485 chips connected together and for now we are only going to send data in 1 direction. By default both the control and data inputs on 1 chip are low. The chip on the other side will be outputting low.

To make the output of the second chip go high you need to turn on the control inputs (disables the receiver and enables the transmitter) and make the input pin high. The output of the second chip will only be high if the control inputs and data input are all high.

If the data input goes low then the output on the 2nd chip will go low.
If the control inputs go low then this chip is no longer sending so the 2nd chip will still go low even if the data input on the first chip is still high